NEW APPROACH IN EMERGENCY OPERATION FOR REDO MITRAL VALVE REPLACEMENT: IS IT JUSTIFIED?

Background: With the progressive aging of western populations, cardiac surgeons is faced with treating an increasing number of critically ill and elderly patients. Controversy exists as to whether the ordinary mid-sternotomy approach to these malfunctioning mitral valves will do the job or a new right thoracotomy approach without cross clamping the aorta is better suited to take care of the problem. The potential to avoid mid-sternotomy surgery in redo patients with little chance of survival and poor quality of life postoperatively would spare unnecessary suffering, reduce operation mortality, and enhance the use of resources.
Methods: We managed 52 cases of severely ill patients admitted to our department on referral from rural areas with malfunctioning prosthetic mitral valves from July 15, 2000 through June 20, 2002. Four patients were women. Preoperatively most of the patients were not moribund, but 67% had hemodynamic instability and 23% experienced cerebral ischemia. All the patients had prosthetic mitral valves. Hospital mortality and morbidity models, based on our overall experience with 52 patients operated on for malfunctioning mitral valves during the period of the study, were developed by means of multivariate logistic regression with preoperative and intraoperative variables used as independent predictors of outcome.
Results: Overall hospital mortality was 14%. There was no intraoperative mortality. All the patients who survived had one or more postoperative complications. Mean hospital stay was 17 days with an average of 11 days and median of 10 days in the intensive care unit.
All of the survivors (6 patients) discharged from the hospital were able to function independently and their survival at 6 months was 100%. Statistical analysis of the overall experience with this new operation for malfunction of prosthetic mitral valves confirmed that via right thoracotomy, the cross - clamping of the aorta is the most important independent patient risk factor associated with 30-day mortality and morbidity.
Conclusion: Operations for critically ill patients involve increased hospital mortality and morbidity. Short-term survival is unfavorable and is associated with a poor quality of life. With additional corroborative studies to endorse the present findings, the use of right thoracotomy approach to have access to malfunctioning mitral valve without the crossclamping of the aorta remains a substantiated concept. In the context of these critically ill patients, the hypothesis that right thoracotomy approach without the cross-clamping of the aorta should be advocated for surgical intervention to save these patients and to conserve resources is supported by the presented data.